Air brush



AIR BRUSH 2 Sheets-Sheet 1 Ruf/7 M. Miner INVENTOR.

BY @.aan

R. M. MINER WWW 19mm Oct. 25, 1955 Filed July 25, 1952 R. M. -MINER AIR BRUSH Oct. 25, 1955 2 Sheets-Sheet 2 Filed July 23, 1952A Ruth M. Miner INVENTOR.

United States Patent O AIR BRUSH Ruth M. Miner, Massillon, Qhio Application July 23, 1952, Serial No. 300,455

4 Claims. (Cl. 299-86) My invention relates to improvements in air brushes, or guns, of the spray nozzle type for use by artists and the like.

The primary object of my invention is to provide a simpliiied air brush with a self-contained easily' renewable and replaceable source' of air under pressure so that con nection to an air pressure line is obviated and the brush may be carried about from place to place ready for use as required.

Another object is to provide such a brush with means for Varying the velocity and amount of spray from the nozzle simultaneously, or separately, selectively by a single finger tip con-trol operative at one side of the brush.

Still another object is tol provide such a brush with a self-contained source' of air under pressure and means automatically controlling discharge of air from the source so that the brush will operate under substantially uniform, predetermined air pressure.

Still another object is to achieve the above objectives in an air brush which is comparatively simple in construction and inexpensive to manufacture and use.

Other and subordinate object-fs, within the purview of my invention, together with the precise nature of my improvements will be readily understood when the succeeding description and claims are read with reference to the drawingsaccompanying and forming part of this specilication.

In said drawings:

Figure I isa view in perspective of my improved air brush in the preferred embodiment thereof;

Figure 2 is an exploded View in perspective of the parts of the air brush disassembled;

Figure 3`is an enlarged view in longitudinal section;

Figure 4 is a View in transverse section taken on the line 4-4 of Figure 3;

Figure 5 is a view in transverse section taken on the line 5-5 of Figure 3;

Figure 6 is a View in transverse section takenon'the line 6-6 of Figure 3, and

Figure 7 is a view in transverse section taken on the line 7-7 of Figure 3.

Referring to the drawings by numerals, the air brush of my invention comprises an elongated body 1 including a central section 2, forming a hand grip, ay front end head section 3, and a rear end hollow cylindrical section 5 forming a capsule holder, the sections 2, 3 being also substantially cylindrical and all of the sections aligned coaxially.

The head section 3 is formed at its rear end with a re duced neck 7 threaded part way into an axial cylindrical chamber 9 in the front end of the central section 2, and with an axial compression chamber 11 in the neck opening into the chamber 9 and into which compressed air is passed by means and for a purpose presently apparent. The function of the chamber 9 will also presently appear.

Means are provided in the head section 3 for mixing ICC Patented Oct. 25, 1955 air and liquid paint and discharging the mixture out of the front end of said section 3 comprising the following. A liquid paint andl air mixing chamber 12 is provided in the head section 3 forwardly of the said chamber 11 at the rear end of a stepped blind, axial bore 13` extending inwardly part way into said section 3 from the frontend thereof and having a screw plug 4 therein forming with said bore 13 the mixing chamber 12.

A liquidA paint receptacle, or reservoir, 14 having a discharge spout 15 is detachably attached to the head section 3 at one side of the body 1 by the spout 15 which is frictionally fitted in a radial bore 16 in said4 section 3 communicating with said chamber 12. A plurality' of mixture discharge bores, or ducts, 17 spaced circumfer entially in the head section 3 around the bore 13 extend' forwardly from the mixing chamber 12 to the front end of said section 3.

A spray nozzle 19 is provided on the front endv of the' head section 3 comprising an outer conical nozzle section 20` threaded, as at 21, onto the section 3, and an inner conical nozzle section 22 fitting in the nozzle section 20 and fitted in the front end of the bore 13. Longitudinal ribs, as at 23, in the outer nozzle section 20 space nozzle sections 19, 20 apart and the mixture discharge bores 17 open and discharge into the space 24 between said nozzle sections 19, 20 so that the mixture will issue out ofthe nozzle 19 in spray form.

Valve controlled duct means in the head section 3 is provided for admitting air from the compression chamber 11 into the mixing chamber 12. This means cornprises a duct 25 inV said section 3 communicating said chamber 11 with a valve chamber 26 in one side of the section 3, and a duct 27 from the valve chamber 26 to the mixing chamber 12, the valve chamber 26- being closed' by a hollow plug 29 threaded into the same. A plunger valve 31 works inthe valve chamber 26 and isy loaded by a` coil spring 32 in said chamber 26 to normally close the' duct 27, `said valve being slidable transversely inr said section 3 toropen the duct 27 in opposition to the spring 32 and having an end 33 projecting into a radial well 34 in the head section 3 diametrically opposite the valve charnber 26.

A needle valve 35 slidably guided in an axial blind bore 36 in the screw plug 14 extends into the nozzle 19 for operation endwise to control the volume of spray discharged from said nozzle.

A common operating means is provided for the plunger valve 31 and the needle valve 35 comprising a linger button 40 at the same side of the head section 3 as the well 34 having a stern 41 slidable inwardly and outwardly of said well 34 against one side of the same and pivotally seated on the end 33 of the plunger valve 31 for rocking movement rearwardly in the well 34 in opposition to a U-shaped leaf spring 45 in said well 34 interposed between said stem 41 and the other side of said well and fastened at onel end in said well, as at 46. A right angled arm 48 on the needle valve 35 slidable in a longitudinal bore 49 in the head section 31 longitudinally of the bore 13 has one end extending into a longitudinal slot 50 in the stem 41. A bifurcated fastener 52 extends through another longitudinal slot 53 in said stem 41 and straddles a notch 54 in the arm 48, the arrangement being such that Said stem 41 is pivotally and slidably connected to said arm 48 so that rearward rocking of the stem 41 will open the needle valve 35 and said stem 41 is slidable inwardly of the Well 34 in engagement with the end 33 of the plunger valve 31 toy open said valve 31. As will be clear, the arm 48, slot 50, notch 54 and fastener 52 provide operating connections between the stem 41 and needle valve 35 whereby said valve may be opened and closed by rocking of the stem 51 rearwardly and forwardly independently of operation of the plunger valve 31, while the stem 41 is movable inwardly of the well 34 independently of operation of the needle valve 35 to open the plunger valve 31. Further, said stem may be rocked to open and close the needle valve 35 and simultaneously slid inwardly and outwardly of the well 34 to open the plunger valve 31 and permit the same to close. It follows that the needle valve 35 and plunger valve 31 may be opened simultaneously in selective degrees, or independently in the selected degree. The plunger valve 31, as will be clear, controls the velocity of the spray at the spray nozzle 19.

The self-contained source of air comprises a commercial capsule 60 of compressed air, or gas, removably titted in the rear cylindrical section with its front end projecting into a forwardly tapering chamber 61 formed in the rear end of the body section 2, said capsule having a neck 62 projecting into a reduced cylindrical, coaxial piston chamber 63 extending forwardly from the chamber 61. Means is provided for puncturing the neck 62 of the capsule 60 comprising an apertured disk piston 65 slidably tted diametrically in the chamber 63 to slide forwardly against an annular front shoulder 66 in said chamber 63, said disk being provided with a rear axial prong 66. The hollow section 5 is threaded onto the rear end of the central section 2 for screw feed forwardly to push the neck 62 against the prong 66 to puncture said neck 62 for discharge of air, or gas, under compression into the chambers 61, 63 to pass forwardly through the apertured disk piston 65. A pad 66 in said section 55 backs the capsule 60.

A compressed air discharge control for the capsule 60 is provided. The control comprises a piston 70 working in the aforementioned chamber 9 and having a rearwardly extending axial stem 71 endwise slidable in an axial bore 72 in the central section 2 extending between the chambers 63 and 9. An axial duct 74 in the piston 70 and stem 71 is adapted to pass air under pressure from the chambers 61, 63 into the chamber 9 forwardly of the piston 70 to enter the compression chamber 11.

A coil spring 76 surrounds the stem 71 in the chamber 9 behind the piston 70 and urges said piston 70 and stem 71 forwardly. An axial, front needle valve member 77 on the piston 65 is provided to close the duct 74 at the rear end of the stem 71 when said piston 70 and stem 71 are moved rearwardly in opposition to the coil spring 76. The neck 7 limits forward movement of the piston 70 and stem 71. Rearward movement of the stern 71 and piston 70 slides the disk piston 65 rearwardly to force the prong 66 into the puncture in the neck 62 of the capsule 60 to stop or reduce discharge from the capsule 60. A back pressure air vent 78 for the chamber 9 is provided in the central section 2 rearwardly of the piston 70.

The described air brush operates as follows. The plunger valve 31 and needle valve 35 being open, piston 70 and stem 71 are moved forwardly by the coil spring 76 and air, or gas, under pressure in the chambers 61, 63, and capsule 60 pass through duct 74 into compression chamber 11 and thence through ducts 25, 27 and valve chamber 26 into the mixing chamber 12 to discharge through the bores 17 to the nozzle 19. The discharge from mixing chamber 12 draws liquid paint from the paint pot or reservoir 14 through spout 15 to mix with the air in the bores 17 and be discharged through the bores in to the nozzle to be formed into spray at the nozzle. The coil spring 76 is designed to be overcome by a given back pressure in the compression chamber 11 working against the front of the piston 70. Up to the given pressure, the pressure in the compression chamber 11 is equalized with the pressure in chambers 61, 63 through the duct 74 and disk piston 65. The surface of the chamber 11 and front of the piston 70 is greater in area than that of the surface of the chambers 61, 63 so that when the plunger valve 31 is closed, or partly closed, if the pressure in the compression chamber 11 builds up in front of the piston 70 above the given pressure, said piston 70 and stem 71 will be forced rearwardly to close the duct 74 and the puncture in the neck 62 of capsule 60, the needle valve member 77 rst entering the rear end of the duct 74 and rearward movement of the stem 71 forcing the disk piston rearwardly in chamber 63 to force the prong 66 into the puncture for closing the same. Thus the air brush is controlled automatically to operate under a given pressure as long as the pressure in the capsule 60 is above the given pressure. When the pressure in the capsule 60 falls below the given pressure, the capsule can be removed and replaced.

The foregoing will, it is believed, suice to impart a clear understanding of my invention, without further explanation.

Manifestly, the invention, as described, is susceptible of modification, without departing from the inventive concept, and right is herein reserved to such modifications as fall within the scope of the appended claims.

Having described the invention, what is claimed as new is:

l. An air brush comprising an elongated body having a spray nozzle on one end and a hollow section on its other end with a compressed air capsule therein puncturable to discharge air under compression, a compression chamber in said body intermediate said ends, means in said body for passing air discharged from said capsule into said compression chamber, an air and liquid paint mixing chamber in said body between said compressed air chamber and nozzle communicating with said nozzle, duct means in said body communicating said chambers to pass compressed air from the compression chamber to the mixing chamber to form an air and paint mixture to be sprayed out of said nozzle, a plunger valve in said body endwise operative to control the passage of air through said duct means whereby to control the velocity of the spray from said nozzle, a needle valve in said body endwise operative in a direction at a right angle to the plunger valve to control the volume of spray from said nozzle, a finger manipulative stem mounted in said body transversely thereof, and means operatively connecting said stem to both valves to operate either or both valves selectively.

2. An air brush according to claim 1 including a capsule puncturing piston in said body movable therein to close the puncture, and a member in said body slidably responsive to a given pressure of air in said compression chamber to move said piston.

3. An air brush according to claim 2, said member comprising a piston and stem having an axial bore for passing air from said capsule to said compression chamber.

4. An air brush according to claim 3, said puncturing piston closing said bore when said piston and stem slide in response to pressure in the compression chamber.

References Cited in the tile of this patent UNITED STATES PATENTS 677,755 Branch July 2, 1901 1,988,637 Tinkham Jan. 22, 1935 2,372,678 McKay Apr. 3, 1945 2,595,317 White May 6, 1952 2,631,891 Kochner et al Mar. 17, 1953 FOREIGN PATENTS 648,020 France Aug. 7, 1928 

